Combined circuit breaker and switch



June 22, 1954 E V, SUNDT COMBINED CIRCUIT BREAKER AND SWITCH Filed July2, 1951 van? VII/Ig..

Patented June 22, 1954 UNITED STATES PATENT OFFICE COMBINED CIRCUITBREAKER AND SWITCH Edward Victor Sundt, Chicago, Ill.

Application July 2, 1951, Serial No. 234,775

This invention relates to a combined circuit breaker and switch.

The principal object of this invention is to provide an improvedcombined circuit breaker and switch embodying a Vsingle switch means foruse in electrical circuits wherein the switch means may be operatedautomatically and freely upon the occurrence of a circuit overloadcondition, wherein manually operated means may operate the switch meansto open and close the circuit as desired, wherein the manually operatedmeans does not interfere with the opening of the switch means upon theoccurrence of an overload condition, which is simple in construction andfoolproof in operation, which is inexpensive to manufacture and install,and which has a long use ful life.

The combined circuit breaker and switch of this invention has many uses,particularly in low voltage circuits such as found in the automotive eldand in ranges up to about 115 volts A. C. Brieiiy, it includes aninsulating base having stationary contacts carried thereby and asnap-acting bimetallic element supported by the base and carryingcontacts for normally engaging the stationary contacts to complete anelectric circuit through the bimetallic element. The bimetallic elementoperates when the temperature thereof increases to a predetermined valueupon the occurrence of an overload condition to separate the contactsfor opening the electric circuit. A lever is pivotally carried by thebasefand has means thereon for engaging the bimetallic element when thelever is movedto one of two positions, an ofi position, to separate thecontacts and open the electric circuit. When the lever is in the otherposition, the on position, it does not interfere with the operation ofthe bimetallic element. A cover is also provided for the base. The levermay be one of a pair of toggle levers, the other toggle lever beingpivotally carried by the cover and extending therethrough to serve as ahandle to be man-` ually manipulated for opening and closing thecontacts forming the switch means.

Preferably, the switch means includes two pairs of contacts so thatdeterioration of the contacts in use is maintained at a minimum. Thestationary contacts are preferably formed on posts extending through thebase and these posts in addition to forming electrical connections alsomay form mounting means for the switch unit.

Further objects of this invention reside in the details of constructionof the combined circuit ture-responsive, bimetallic element I8.

breaker and switch and the cooperative relationships between thecomponent parts thereof.

Other objects and advantages of this invention will become apparent tothose skilled in the art upon reference tothe accompanyingspeciijlcation, claims and drawing, in which:

Fig. 1 is a vertical sectional view through the combined circuit breakerand switch of this invention showing the same in off position;

Fig. 2 is a view similar to Fig. 1 but showing the combined circuitbreaker and switch in on position with the electric circuit closed;

Fig. 3 is a view similar to Fig. 2 showing the combined circuit breakerand switch in on position but with the contacts separated due to theexistence of an overload condition in the electric circuit;

Fig. 4 is a vertical sectional View taken substantially along the line4--4 of Fig. 1;

Fig. 5 is a horizontal sectional View taken substantially along the line5--5` of Fig. 1;

Fig. 6 is an exploded perspective View of the snap-acting bimetallicelement and one of the toggle levers associated therewith.

The combined circuit breaker and switch of this invention is generallydesignated at I0. It includes a base II made of suitable electricalinsulating material such as molded Bakelite or the like. Secured in thebase II, preferably during the molding operation, are a pair of posts I2having shoulders I3 and I4 and extension I5 for iirmly securing theposts in the base II.

The outer ends of the posts are preferably screwthreaded for the purposeof making electrical connections thereto and for mounting the unit. Theinner ends of the posts I 2 are provided with stationary contacts IB. Inthis respect the contacts I6 may be formed of suitable contact materialand secured to the ends of the posts as by welding or the like.

The combined circuit breaker and switch of this invention utilizes asnap-acting, tempera- This bimetallic element I8 is elongated and isprovided with a pair of longitudinally extending slits I9 to form acentral leg 2i] and a pair of outer legs 2I. The center leg 26 isslightly longer than the outer legs 2| and is also crowned to providesnap-acting characteristics to the bimetallic element. A pair ofcontacts made of suitable contact material are secured to the bimetallicelement adjacent the ends thereof as by welding or the like. The movablecontacts 22 are adapted to engage the stationary contacts IE to completean electric circuit through the bimetallic element I8 across the contactposts I2.

The central leg 2D of the bimetallic element I8 is centrally providedwith a rectangular hole 24 for receiving a rectangular post 25 having anenlarged head 26. The post 25 is adjustably received in a rectangularhole 2'! in the base II, the post being received therein by a force nt.In this respect the post Z is provided with serrations for assisting 'inmaintaining the post `in proper position in the'hole 21. A spring 28vencompasses the post and extends between the bimetallic element I`8 andthe base II for maintaining the bimetallic elementagainst.theehlargedhead 26 of the post. "Thus, the post25 and the spring 28 operate tomount.:the :bimetallic element I8 on the base II. Whenthe bimetallicelement is being so mounted, kthe post25"is"in serted into the base I!to a predeterminedpoint properly to position the bimetallic element I8for y.the purpose .of Calibrating. -the same .with respect totemperature.

When theicondition .ofthe electric .circuit is normal, .the .temperature.of the vbimetallic element IS is such .that theicontactsn22. .carriedthereby engage the stationarycontacts I5 .for completing .the electric.circuit as illustratedfin Fig. 2; When,.however, -an .overload conditionoccurs inthe electriccircuit, thetemperatureof the bimetallic element.I8 increases. and when the' temperaturedncreases to apredeterminedvalue determined .by thecalibration of the i-unit, then the bimetallicelement snaps to. the position illustrated in Fig.- 3.for. .separatingthe-.contacts 22 :fromV the stationarycontacts I3 This breaks theelectric circuit. .Whenl .the temperaturev of the bimetallic'element I8decreasesto a precietermined lower value, thebimetallic elementthensnaps back Yto `the-.position illustrated .in Fig. 2 forre-closing .thecontacts. the. .particu1ar arrangement 'illustrated -here in .the.drawingfthe bimetallicelement will continuato cycleso long as "theoverload condition exists in the .circuit The substantially rectangularhole in the central leg 20. in the bimetallicelement'lland.thereotangularpostZB .operate Ato prevent .rotation of thebimetallic element I3 so thatthe contacts22 and I6 -are maintained. inalignment.

.A vcover 3| is suitably securedto thefbase II and restsagainst ashoulder' .3c provided onthe peripheryof the base H."`.The.cover 3I .maybe secured .tothe base II as by 'crimpingthefsame thereto.' On oppositesides ofthe centralpostl the base I l is provided with a pai-rof.recesses..32.

` A U-shap'ed lever 34 overlies bimetallic .ele, ment 18 and has itsends 35 received inthe recesees32 forthe purpose of pivotally mountingthelever 34cnth`e base I I. The lever v'34.is pro vided with a Apair `ofsurfaces 36 for'lengaging the Iupper surface offthe base II to limitpivotal movement in one direction offthefleverf34. A`It is also providedwitha pair fof. surfaces 31 `for engaging the 'upper'.'surface of:thefbase I I lfor permitting .limitedsmovementthereof'.1in-theoppositcfdfirection. fAs .shown in .1i,thc` sure face3l' limits the pivotal movement of the lever 34..in. one directionand-as shown in Figs. 2`and. 3 thewasurface .limits the pivotalmovernentin the .opposite direction. Thus, `the lcveri34ris pivotally..mounted.for movement between two positions. .Thelever-34 also carries a pairoff-pins 38 belowthe vbimetallic.element Ivx which .are adaptedto engage.the ,i under sides .of .the outer legs 2`I "of the bimetallic elementI8. When the lever34 is .in the position illustrated. in Figs. 2

l'22 thereof away from the stationary contacts I6.

Thus, when the lever 34 is in the position illusfifti'ated in Fig. l,the contacts are separated and .y .the..circuit opened .independently ofoverload conditions in the circuit. The top of the leverJ34wis-:providedvwith a pair of projections 39 and a recess 40therebetween which are utilized for thepurposeof moving the lever 34between the two'xpo'sitions.

The lever 34 forms one lever of a pair of toggle levers, the-.othertoggle lever .being-designatcdat 42. This toggle lever `42 is providedwithasphericalsurface 43 .whichfengages a .socket .44 .formedinthercover 3I..A..plate 45 .alsohaving a socket 48.is-.secured to the.cover 3| by any .suitable means suchasrivets 41. The .sockets 44.and4.6 and thespherical .surface ..43 .operate pivotally. to mountthektoggle`lever.42. in the .cover 3I. The toggle. lever.42 extendsthrcughthecoveril .and the. .outenend .thereof .seri/'esas ahandle .to..bemanually manipulated. The toggle lever.42..is.internally .provided withabore .48.in which` is slidably .mounted plunger .49 .which is. springpressed toward. the vtoggle lever 34 .bymeansof a .spring .5.0 within.the bore .48. .The spring pressed .plunger 49 of. thetoggle .lever.42.. engages in the recess 48 between the projections .318 ,to form an-operatingconnection between .the`v two toggle levers .34 and .42. l

.When the toggle levers .34 .and A4.2 .are in the position illustratedin Fig. 1,.that is, l.the off positionfthey .are maintained in thatposition by the spring .fwacting on .the plunger vII!! and.` themovable-.contacts22 are separated fromthe ystationary. contacts I 6 .for.maintaining the electric .circuitiopen .When,y however, the togglelevers 34 .and .42 :are moved to the position .illustrated in V2, .that`is,.the on position, they are maintainedin thatposition bythe spring50. `acting. on .the plungerf49 .and .the `pins V38. are .movedaway-romthe bimetallic elementl3sothat the movable contacts l.22engage-the stationarycontacts YI6..tc.cornplete .the electriccircuit.Iincw an overload condition. should occurinth'e-z-electric` circuit, thetemperature of .the bimetallic element yHzis :increased to-separate themovable contacts 22-.from the stationary contacts I.6,a'as illustrated-in Fig. .3., to .open .the electric circuit.

Thus,- the toggle levers34 and Y42 cooperating with .the .bimetallic.element `Itioperate "a manually operated switch-;foropeningand closing.the `electric Vcircuit 4as desired, this @being accomplished by,movingthe toggle levers between the foi land fonapositions When, however, thetoggle levers 34 and `42 :are moved to-the .fon .position, then thebimetallic element 18 operates vfreelyand `automatically as a circuitbreaker` to `open .and -close the Yelectric circuit in accordance withoverload .conditionstherein `While .for-.purposes of illustration one.form of this..invention.has been. disclosed, otherforms thereof maybecomeapparent .to .those lskilled in the art upon reference to thisdisclosure and. tahereforathisA invention` is to be` limited only bythescope of' the, appended claims.

`tact to complete an electric circuit through the bimetallic element,said snap acting bimetallic element operating when the temperaturethereof increases to a predetermined value to separate the contacts foropening the electric circuit and operating when the temperature thereofdecreases to a predetermined value to engage the contacts for closingthe electric circuit, and a pair of spring biased togglelevers includinga lever pivotally carried by the base and movable between two positionsand maintained at either of said two positions and having means thereonfree from the bimetallic element when the lever is in one position topermit free operation of the bimetallic element but engaging thebimetallic element when the lever is in the other posivtion'to separatethe contacts and open the electric circuit.

2. A combined circuit breaker and switch comprising, an insulating base,a stationary contact carried by the base, a snap acting bimetallicelement supported'by the `base and carrying a contact for normallyengaging the stationary contact to complete an electric circuit throughthe bimetallic element, said snap acting bimetallic element operatingwhen the temperature thereof increases to a predetermined value toseparate the contacts for opening the electric circuit and operatingwhen the temperature thereof decreases to a predetermined value toengage the contacts for closing the electric circuit, a cover carried bythe base, and a pair of spring biased toggle levers movable between twopositions and maintained at either or" said two positions, one of thelevers being pivotally carried' by the cover and extending therethroughto serve as a handle to bemanually manipulated, ,and the other leverbeing pivotally carried by the base and having means thereon free fromthe bimetallic element when the toggle levers are in one position topermit free operation of the bimetallic element but engaging thebimetallic element when the toggle levers are in the other position toseparate the contactsv and open the electric circuit.

3. A combined circuit breaker and switch comprising, an insulating base,a stationary contact carried by the base, a snap acting bimetallicelement supported by the base and carrying a Contact for normallyengaging the stationary Y contact to complete an electric circuitthrough the bimetallic element, said snap acting bimetallic elementoperating when the temperature thereof increases to a predeterminedvalue to separate the contacts for opening the electric circuit, a covercarried by the base, and a pair of 'toggle levers including a rst leverpivotally carried by the cover and extending therethrough with its outerend serving as a handle to be manually manipulated and with its innerend provided with a spring pressed plunger, and a second lever pivotallycarried by the base and engaged by the spring pressed plunger and havingmeans thereon for engagging the bimetallic element when the togglelevers are moved to one positionto separate the contacts .and open theelectric circuit.

4. A combined circuit breaker and switch comprising, an insulating base,a stationary contact carried by the base, a snap acting bimetallicelement supported by the base and carrying a contact for normallyengaging the stationary contact to complete an electric circuit throughthe bimetallic element, said snap acting bimetallic element operatingwhen the temperature thereof increases to a predetermined value toseparate the contacts for opening the electric circuit and operatingwhen the temperature thereof decreases to a predetermined value toengage the contacts for opening the electric circuit, a cover carried bythe base, and a pair or toggle levers movable between two positions andincluding .a first lever pivotally carried by the cover and extendingtherethrough with its outer end serving as a handle to be manuallymanipulated and with its inner end provided with a spring pressedplunger, and a second lever pivotally carried by the base and engaged bythe spring pressed plunger and having means thereon free from thebimetallic element when the toggle levers are in one position to permitfree operation of the bimetallic element but engaging the bimetallicelement when the toggle levers are in the other vposition to separatethe contacts and open the electric circuit.

5. A combined circuit breaker and switch comprising, an insulating base,a pair of stationary contacts carried by the base, a snap actingbimetallic element having a pair of contacts for normally engaging thestationary contacts to complete an electric circuit through thebimetallic element, means between the contacts of the bimetallic elementfor supporting the bimetallic element on the base, said snap actingbimetallic element operating when the temperature thereof increases to apredetermined value to separate the contacts carried by the bimetallic.elementfrom the stationary contacts for opening the electric circuit,and a lever pivotally carried by the base and having means thereon forengaging the bimetallic element adjacent its mounting means when thelever is moved to one position to separate the contacts carried by thebimetallic element from the stationary contacts and open the electriccircuit.

6. A combined circuit breaker and switch comprising, an insulating base,a pair of stationary contacts carried by the base, a snap actingbimetallic element having a pair of contacts for normally engaging thestationary contacts to complete an electric circuit through thebimetallic element, means between the contacts of the bimetallic elementfor supporting the bimetallic element on the base, said snap actingbimetallic element operating when the temperature therof increases to apredetermined value to separate the contacts carried by the bimetallicelement from the stationary contacts for opening the electric circuit, acover carried by the base, and a pairof toggle levers, one of the leversbeing pivotally carried by the cover and extending there-'- through toserve as a handle to be manually manipulated, and the other lever beingpivotally carried by the base and having means thereon for engaging thebimetallic element adjacent its mounting means when the toggle leversare moved to one position to separate the contacts carriedrby thebimetallic element from the sta'-Y tionary contacts and open theelectric circuit.

'7. A combined circuit breaker and switch comprising, an insulatingbase, a pair of stationary contacts carried by the base, an elongatedsnap acting bimetallic element having a contact adjacent each end fornormally engaging the stationary contacts to complete an electriccircuit aaeenaec v throughy .thebimetalhc element, `said elongated"snapractingfbimetallic[element having a pair: `of

separate thecontacts carried by .the bimeta-llic v elementwfrom the.stationary contacts and :open the electric; circuit.

-;8. .1A combined circuit breaker and. Vswitchcon'iprising;:in-.insulating ibase,` a pair of stationary contactsfcarried bythebase, an elongated snap actingk bimetallic lelement having a contactladjacent 'each end `for. normally engaging fthe stationary contacts to`complete an `electric circuit through the biinetallic element, `saidelongated snap acting birnetallic element having apair'of longitudinalslitsridefining a pair of outer legs andwawcentral Aleg and 'the'`central leg being crowned,means for .mounting the central-leg of thebimetallicielementon the basa-said snapacting bimetallic elementRoperating when the teinperature thereof :increases to4 a predeterminedvalue-torseparate the contactscarried by the oimetallic'i-element 4fromthe 'stationary contacts .forcopeningithe electric circuit, a covercarried .bythe base-,wand `a pair oftoggle levers, one :of

thealeversr-being pivotally carried bythe cover andrextendingtherethrough* to serve as ar'handle to ibevmanually manipulated, Vand'the-other lever being ,-pivotally'carried` by the4 base `and havingmeans,thereonforengaging theouter. legs of the bimetallic elementwhenthetogglelevers are moved ritoione position to separate, the contactscarried-by Ythe birnetallic element from the stationarv contacts :andiopen the lelectric circuit.

9. A circuit breaker comprising, ian insulating baseshaving acentralrectangular opening, a pair of #posts -rsecured` to and extendingthrough the baseion'opposite sidesfof the central-opening andeachrhaving a'stationarycontact on its end,.an elongated-snap v,actingbirnetallic `element ihaving a contact'adjacent4 each-,end for normallyengaging therstationaryv contactsV to .complete an electric i circuitthrough` the bimetallic element,` ysaid elongated snap acting bimetallicelement having apair o'flongitudinalI slits defining a .pair ofouterlegs iafnd azcentral leg and `the central legbeing crowned and providedwith a central: rectangular opening; a'central'postof rectangular crosssection `having a head "and extending through `the central'opening .inth'ebimeta-llic element and adjustablyfsecured in the central openinginthe base-springmeans on the central post between thewbimetallioelement and the base for maintainingthe bimetallic element against thehead on theI central post; said snap acting bimetallic elementoperatingwhen the temperature thereof increases to a :predetermined value toseparate the contacts ecarriedfby the' bimetallic "element from' thestationary contacts 'for opening the elecm tric circuit.

10.- 'A fcombined circuit breaker `and switch comprisingyan insulatingbeschaving a central rectangular opening,I a pairr of posts securedl toand extending through thebase on opposite sides 'of-'the centrallopening :and each having astav tionary contact on its:endwanielongatedyeinap .acting .fbimetallic elementl having .a Contactr adja- `centzeaclogenrl foranormallyengaging .the stationary -contacts:to-rcomplete. Yannlelectric :circuit through the bimetallic element,`said elongated snap 1 acting `bimetallic element having. a. .'pairfioflongitudinal slitsfdening a pairfof outerlegszand a central leg and .thecentralleg 4being:crowned and provided with a central rectangularopening, a centralipost of reotangularlcrossfsectionx-having a head andextending through .thefoentraiff'opening in thebirnetallic:elementiandadjustablyxse- 4cured in the central.opening-.inthe.baseaispring :means on thecentral `post between the4bimetallc element and- .thebaseffor'maintaining thepbimetallic elementagainst; theJ head ,on z the `central post, said snap` acting`bimetallic element zoper'atling when the-temperature thereoffincreasessto a `nredetermined val-ue toseparateithe contacts .carriedbylthe :bimetallic elementgfrom the Astationary contacts for :opening'the .electrica` circuit, a

pair of .recesses :in the base :on oppositesides'fof the central post,Aal U shaped leverextending 'over the birnetallic element and having itsends pivotally .mounted :in thefrecesses, and Ameans `onthe leveriorengaging theouter legs ofrthetbimetallic element when the lever .ismoved'toloneposition to'separate the oontactscarried bythelbimetallicelement `from the `stationary contacts .l and zopen the lelectriccircuit.

1l. A `combined `circuitbreaker iandwswitch comprising, an insulating.base having acentral rectangular opening, a Vpair ofzposts vsecuredzto.and extending through the base onaopposite'sides of the central`opening andeach 4l'iavingaYstationary contact on its end; an='elongated.;snap

`acting .himetallic element havingxa :contactU ad- `iacent each end fornormally engagingthenstationary contactsto 'complete annelectric circuitthrough vthe.'bimetallic element; saidfelongated snap actingbimetallicel'ement having a :pair lof Ylongitudinal slits .defining apair Vof outer legs and a 'central leg and `the 4.central-:leg` beingcrowned and providedwith i a centralrectangular opening, a 4central postof ^rectangularicrossasec- `tion lzaving a `head 'and 1 extendingthrou'ghlthe central openingin the ibimetallicrelementiand adjustably`secured in the central openingcin :the base, spring `means ont-hecentral post lbetvsreeu thebimetallicel ementand the basef'ormaintainingizthe `bimetallic element :against theuhe'a-:son thecentral post, i said acting Abirrretallic element -operating when thetemperaturethereof increases -to a `predetermined'.value to separate thecontacts carried ibythe bimetallic element from the stationary contacts`fortopening"theaelectric circuit, a pair of recesses 'in :thebase ronoppositesides of the centralr post, Aa 'Ueshaped lever extending :over:the birnetallic :element .and having endspivotally 'mounted` inftherecesses, and means ontheilever forengaging theiouter legs of thebimetallic element whenathe-"leverpis moved to `one position to separatetheicontacts carried by the bimetallic `element from the stationarycontacts and open theelectricfrcircuit a cover carried by the basefsaidU-shaped `lever formingone of a pair of toggle'levers, theiother togglelever being pivotallycarried byfthe Icover and extending therethroughwith its .outer end serving a handle to be manuallyamanipulateo' andwith its inner end provided with` a 4spring pressed plunger engaging theU-shaped' lever.

.12.-A combined circuit breaker` .and switch comprising,l an insulatingbase, a 7pairdof Astationary contactscarried by the base, asnap. actingbimetallic element having a pair of contacts for normally engaging thestationary contacts to complete an electric circuit through thebimetallic element, means between the contacts of tne bimetallic elementfor supporting the bimetallic element on the base, said snap actingbimetallic element operating when the temperature thereof increases to apredetermined value to separate the contacts carried by the bimetallicelement from the stationary contacts for opening the electric circuit, apair of recesses in the base on opposite sides of the mounting means forthe bimetallic element, a Ushaped lever extending over the bimetallicelement and having its ends pivotally mounted in the recesses, and meanson the lever for engaging the bimetallic element adjacent its mountingmeans when the lever is moved to one position to separate the contactscarried by the bimetallic element from the sta-- tionary contacts andopen the circuit.

13. A combined circuit breaker and switch comprising, an insulatingbase, a pair of stationary contacts carried by the base, a snap actingbimetallic element having a pair of contacts for normally engaging thestationary contacts to complete an electric circuit through thebimetallic element, means between the contacts of the bmetallic elementfor supporting the bimetallic element on the base, said snap actingbimetallic element operating when the temperature thereof increases to apredetermined value to separate the contacts carried by the bimetallicelement from the stationary contacts for opening the electric circuit, apair of recesses in the base on opposite sides of the mounting means forthe bimetallic element, a U-shaped lever extending over the bimetallicelement and having its ends pivotally mounted in the recesses, and meanson the lever for engaging the bimetallic element adjacent its mountingmeans when the lever is 4 moved to one position to separate the contactscarried by the bimetallic element from the stationary contacts and openthe circuit, a cover carried by the base, said U-shaped lever formingone of a pair of toggle levers, the other toggle lever being pivotallycarried by the cover and extending therethrough with its outer endserving as a handle to be manually manipulated and with its inner endprovided with a spring pressed plunger engaging the U-shaped lever.

14. A combined circuit breaker and switch comprising, an insulatingbase, a stationary contact carried by the base, a snap acting bimetallicelement supported by the base and carrying a contact for normallyengaging the stationary ccntact to complete an electric circuit throughthe bimetallic element, said snap acting bimetallic element operatingwhen the temperature thereof increases tc a predetermined value toseparate the contacts for opening the electric circuit and operatingwhen the temperature thereof decreases to a predetermined value toengage the contacts for opening the electric circuit, a cover carried bythe base, and spring biased lever means carried by the base andextending through the cover and movable between two positions andmaintained at either of said two positions and having means thereon freefrom the birnetallic element when the lever means is in one position topermit free operation of the bimetallic element but engaging thebimetallic element when the lever means is in the other position toseparate the contacts and open the electric circult.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 2,249,837 Lee July 22, 1941 2,462,244 Wise Feb. 22, 19492,520,873 Bean Aug. 29, 1950 2,520,874 Bean Aug. 29, 1950

